At some point recently (can’t pin point exactly when) the Android SmartThings Classic app (v2.16.1) seems to have issues with my Zooz Zen21 Z-Wave 3-way switch. Had been working fine for the last year or so. The app reports back the correct On/Off status, but I can no longer command it On or Off (or change how the switch’s LED operates). The other odd thing is that in IDE it shows that the switch is part of the Smarthing’s SmartLighting routine, but not according to the Android SmartThings Classic app (that I have to trigger it and another light when certain conditions are present). The other non-Zooz switch is still in that routine and works fine. I have tried removing the switch from the devices list both via the Smarthing Classic App (properly excluded) and via IDE and then re-installed. Same issue. Hub firmware is 000.022.0013.

I think there maybe a recently introduced bug to the last SmartThings Classic android update as all looks fine in IDE and status is always updated to reflect proper on/off status on both IDE and ST Classic app. The switch itself is working just fine manually.

This one has me stumped…and I have had lots of strange issue over the years that usually just are fixed with just excluding and re-installing the device.

Well…had to change the device handler to the generic “Z-Wave Relay” and the switch can now be commanded properly. Wondering if ST had an update that broke Don Caruana’s Zooz Zen21 Switch v2 device handler somehow.